Testing was done using Intel Burn Test (IBT) with the AVX instruction set. The reason I use this instead of Prime95 with this setup is that it pushes our i5 2500K a whole lot harder, giving us a better sense of load temps. Most of the testing was done at the high memory setting for a single pass. While admittedly this in no way would qualify the chip as stable when overclocking, it gives us a realistic idea of what temps it will be hitting.

*Please note we still have a bug in Hardware Monitor causing it to change the max readings for all the system fans to impossible numbers after a minute of IBT running. Prior to it flaking out however we were just above 1600rpm under load at all times.

Not exactly impressive results, but this cooler is supposed to be a compact cooler aimed at gamers. Any self respecting, framerate loving gamer is of course going to overclock their CPU. So we put the S40 through a short overclocking session and here is how it did:

Ouch, unfortunately this was one of the most poor overclocking coolers that we’ve tested. Even with the fan cranking away above it’s rated speed, it was still extremely hot. As expected, the fan was still very quiet even at it’s highest speed.

There are a couple of things that could cause this. The first in my opinion would be the thermal paste. It’s likely there just wasn’t enough and that the quality of paste is low. An easy fix would be to get something like Prolima Tech PK-1 and reapply. The other thing could be the fan. While a quiet fan is nice, it just didn’t seem to be moving that much air through to the back of the cooler. Again replacing the fan would probably help.